To be diagnosed clinically depressed, which usually means intervention such as medication and/or counseling, certain guidelines have to be met.

These are directly from the American Psychiatric Association’s website.

Depression (major depressive disorder) is a common and serious medical illness that negatively affects how you feel, the way you think and how you act. Fortunately, it is also treatable. Depression causes feelings of sadness and/or a loss of interest in activities once enjoyed. It can lead to a variety of emotional and physical problems and can decrease a person’s ability to function at work and at home.

Depression symptoms can vary from mild to severe and can include:

• Feeling sad or having a depressed mood
• Loss of interest or pleasure in activities once enjoyed
• Changes in appetite — weight loss or gain unrelated to dieting
• Trouble sleeping or sleeping too much
• Loss of energy or increased fatigue
• Increase in purposeless physical activity (e.g., hand-wringing or pacing) or slowed movements and speech (actions observable by others)
• Feeling worthless or guilty
• Difficulty thinking, concentrating or making decisions
• Thoughts of death or suicide

You must experience at least five of these symptoms and must last at least two weeks for a diagnosis of depression.

Also, medical conditions (e.g., thyroid problems, a brain tumor or vitamin deficiency) can mimic symptoms of depression so it is important to rule out general medical causes.